Process and apparatus for forming sheet glass



Au-g. 1l, 1931. w. E. NoBBE PROCESS AND APPARATUS FOR FORMING SHEET GLASS Filed Jari. 19, 1928 2 Sheets-sheet 1 g1/nannte@ d1/ham E /Vobbe Aug. 11, 1931-. w. E. NoBBE PROCESS AND APPARATUS FOR FORMING SHEET GLASS `Filed Jan. 19, 1928 2 Sheets-Sheet 2 E A, :L QILEQ .m NV. E; m m

EKJ. :SPIEL Patented'Aug. 11, 1.9.31

UNITED sra'rizs PATENTL OFFICE WILLIAM E.` NOBIBE, F TOLEDO, OHIO, .ASSIGNOR TON LIBBEY-OWENS-FORD GLASS COMPANY, OE TOLEDO, OHIO, A CORPORATION O-F OHIO rnqonss Ann APPARATUS son ronMING SHEET GLASS Application 'led `Tanuary 19, 1928. Serial No. 247,855.

The present invention relates to a process and apparatus for forming sheet glass.

The glass sheets produced in accordance with this invention are especially well adapted for use as plate glass blanks but obviously they are not necessarily restricted to such use.

One of the objects of this invention is to provide a. process and apparatus of this character whereby sheet glass may be quickly and z easily formed and sheets which are exceptionally lat vand of substantially predetermined dimensions obtained.

Another object of this invention isA to provide a process and apparatus of this nature wherein a stream of molten glass 1s directed 1n a substantially horizontal path and gradually reduced through' successive stagesto a sheet of mensions. Y Still another object of this invention is to Isubstantially predetermined diprovide such a process and apparatus wherein the molten glass is rst created ina furnace and then directed in a substantially horizontal path and reduced toA a sheet of substantially predetermined dimensions by spreading it outwardly from its center.

A still further object of this invention is to provide a process and apparatus wherein a stream of molten glass istiowed from a source of molten glass and passed in a substantially horizontal plane between a plurality of pairsor sets of forming members ewhich serve to gradually reduce the stream lto a sheet of substantially predetermined thickness and width, the apparatus preferably including means for driving the forming members at4 respectively increasing speeds to maintain proper longitudinal tension in the sheet being formed.

Still another object of the invention is to' provide a process and apparatus `of this chari acter wherein a stream ofmo'lten glass. is

ilowed from a furnacein a substantially horizontal path and passed between a plurality of spaced pairs or sets of forming members or rolls which serve to gradually reduce the stream to sheet form together with means arranged between the pairs or sets of forming members for supporting the invention will be made more apparent as this description proceeds, especially when considered in connection with the accompanying drawings wherein: l Figure 1 is a fragmentary vertical longi- Vsheet forming ,apparatus constructed in accordance with this invention.

Figure 2 is a. -top plan view offthe sheet forming meansl illustrated in Figure l1.

Figures 3 to 9 inclusive are fragmentary 55 vertical sectional views taken substantially on the planes indicated by lines 3 3, 4 4, 5 5, 6 6, 7 7, 8 8, and 9 9 of Figure 1 showing the various pairs of sheet forming rolls and the Sheet supporting means located 'mtherebetween.

Figure l0 is a fragmentary vertical longitudinal sectional view ,through a modified f A form of sheet-forming apparatus, and

Figures 11t0 15 inclusive are detail verti- 75 cal sectional views taken substantially on the planes indicated bv lines 11 11, '12 12,

13- 13, 141-14, Vana 15-15 in Figure 1o showing the construction of the various pairs of sheet forming rolls and of the sheet supporting means located therebetween. Referring now more' particularly to Figures 1 to 9 of the drawings it will be noted" that Ithere is fragmentarilyillustrated one end of a furnace or other suitable container a5 16 wherein is produced a mass of molten glass 17. The furnace is provided in one wall thereof with an outlet opening or spout 18 through which the molten glass is adapted to flow in a relatively thick narrow stream 19. 90

The outlet opening 18 is preferably arranged in the wall 20ct the furnace somewhat below the normal level of the mass onA/lten glass therein and is relatively narrow as seen more particularly from an examination 'of Figure 2 so that the relatively thick narrow stream 19 will be caused to How therefrom under the head pressure of the mass of molten glass 17.-

The stream of molten glass 19 which issues 10o tudinal sectional viewthrough an improved 30 or flows from the outlet spout 18 .is arranged in a substantially horizontal plane and in accordance with this invention the stream is directed in a substantially horizontal path during the time it is reduced to sheet form. For reducing the stream of molten glass to sheet form and for directing it in a substantially horizontal path there is provided a plurality of pairs or sets of forming rolls 21, 22, 23 and 24 arranged in substantially horizontal alignment with one another with the rolls of each pair being spaced apart to permit the glass to pass therebetween.

The several pairs of rolls are of respectively increasing length from theI rolls 21 arranged nearest the furnace to the rolls 24 located most remote therefrom. The rolls 21, 22 and 23 gradually taper from their centers towards their ends while the most remote rolls\ 24 are cylindrical to `form a straight sheet for ming pass having parallel sides.

The degree of taper of the several sets of rolls gradually decreased from the foremost rolls 21 to the most 4remote pair so that the rolls gradually approach cylindrical form. 'lj-he cylindrical rolls 24 are arranged relatively c'lose together, the space therebetween determining the thickness of the sheet produced.

w Due to the particular construction of the forming rollsthe space between the rolls of each succeeding pair is less than the space of the rolls of(tbe preceding pair so that the` streamf'of molten glass which is directed therebetween is gradually reduced in thickness. Furthermore, by reason of the forma# tion of the rolls, the glass is spread outward-- ly from the center towards the opposite ends thereof, and thus the stream while being gradually reduced in thickness issimultaneously. increased in width so that the resulting sheet will be of substantially predetermined dimensions. l

-Located between adjacentA pairs of rolls 21, 22, 23.,and 24 are supporting tables vor members 25, 26 and 27 respectivelyand located ad]acent to but beyond the most remote pair .of rolls 24 is a supporting table orcmember" 28. The top or upper faces or surfaces 29, 30 and 31 of the tables 25, 26 and 27 respectlvely are curved or shaped to conform to the 'longitudinal contour of the lowermost rolls .and beneath the stream or sheet so as to support the sheet or stream during its formative period and prevent the same from sagging.

As shown the longitudinal sides 32 of these supporting tables may be curved or shaped to substantially conform to the circumference of the rolls so that the upper surfaces of these supporting tables may be made rela- 4"outwardly .ture control medium through the hollow shafts 33 thereof and the temperature of the supporting tables 25, 26, 27 and 28 may be 'controlled/by circulating a temperature control medium therethrough by means of pipes or conduits 34. The upper surface 35 of supporting table 28 will be substantially flat so as to properly support the sheet as it leaves the pair of forming rolls 24.

The flow of the relatively thick narrow streamof molten glass issuing from the outlet opening or spout' 18 is controlled'or regulated by the adjacent pair of rolls 21 but obviously the amount of glass flowing from the furnace may be controlled by "an adjustable gate o'r closure member (not-shown) if desired. A 4 A.

The stream of molten glass after flowing from-outlet spout 18 passes'betweent-he several pairs 4of rolls whereby it is reduced` through successive lstagest to ajs leet of substantially predetermined dimensions, eaclr succeeding pair of rolls serving to decrease the thickness of the stream while simultaneously increasing its width as clearly -illus'f trated in Figures 2 to 9 inclusive. Inl other words, there is first created a mass of-moltensoA successive stages to a sheetl of substantiallyl predetermined dimensions by, spreading dfrom its center.

The' formed sheet 36 after passing over supporting table 28 is carried upon a plurality`of rolls or other suitable conveying means 37 into 4an-annealing lehr 38 wherein it is supported vand carried along on a plurality of horizontally arranged supporting rolls 39.

Each l.of'the rolls of the several pairs of posite ends with collars/10 which serveA to prevent the 'molten glass from flowing outwardly beyond ,thev endsfof the rolls. The several pairs of rolls as well as the supporting. tables are preferably locatedwithin a ,'rolls is also preferablyprovided at its opv fno chamber 'or compartment 41 and the tem-A perature of this compartment as well as the temperature of the glass as it passes between the rolls can be controlledby burners or other "suitable heating'means 42 to thus maintainl the gla s in a plastic workable condition. The sTev ral, pairs of forming rolls may, if desired, be driv n (by means not shown) at progressively `icreasing speeds to maintain the sheet under longitudinal tension.

In Figures 10 to 15 a modified'form of construction is illustrated. In this form the upper and'lower rolls of each pair of rolls are of different longitudinal contour, the upper rolls 431, 44', 45 and 46 of the several pairs of rolls are similar in shape and contour to the upper rolls of the pairs of rolls 21, 22, 23

andi/24 of the previously described construcof rolls is straight or in other words parallel with thea'xis of rotation of the rolls. j

Located between the pairs of rolls and beyond the most remote pair of rolls are supporting members or tables 48, the upper surfaces 49 of which are flat. y These iiat surfaces 49 of the supporting tables 48 engage the lower surface of the sheet during the formative period to support the same between the several pairs of forming rolls and immediately after the sheet leaves the final pair of forming rolls. Both 'the forming rolls and the supporting tables may have the temperature thereof controlled by circulatin'g therethrough a temperature control medium in the same manner as described in the `previously referred to form of construction. l

As in the previously described form of construction the 'relatively thick narrow' stream of molten glass is reduced through successive stages to form a sheet 'of substantially predetermined dimensions. The present form dill'ers from the previously described form, however, in that theumass of glass or thesheet during the formative period is spread from its center outwardly to its opposite ends only by the upper rolls, the bottom of'the Vmass or sheet remaining fiat or parallel with the axis of rotation of the lowermost rolls. However, the effect is the same as the sheetis gradually reduced 'in thickness and simultaneously increased in width so that the resulting sheet will be of substantially predetermined dimensions.

While an embodiment of the invention has been described and illustrated herein somewhatin `detail it will be readily apparent to those skilled in this art that various changes, modifications and rearrangements may be reand scope of this inventi n and to this end sorted to without depaig from thespirit reservation is made to ke such changes as may come within the purview of theaccompanying claims.

I claim:

1. In sheet glass forming apparatus, lthe combination with a furnace containing a mass of molten glass and provided with an outlet through which a stream of molten glass issues, of means for directing the stream ina substantially horizontalpath and Y reducing the same through ysuccesslve stagesto sheet form, including a plurality of pairs of sheet forming rolls, said rolls being conl structed to reduce the thickness of the stream first at its center andto then subsequently reduce the end portions tothe same thickness, and means for`supporting the stream of glass` between adjacent pairs of forming rolls to prevent sagging of the thinner portions of the stream with respect to the thicker portions thereof.

2. In sheet glass forming apparatus, the

combination with a furnace containing a mass of molten glass and provided with an reducing the same through successive stages Yto sheet form, including a plurality of pairs of sheet forming rolls. said rolls being cpustructed to reduce the thickness of the stream duce the end portions through successive stages tothe same thickness by spreading the glass outwardly from its center, and means for supporting the stream of glass between adjacent pairs of forming rolls to prevent the central thinner portion of the' stream from sagging relative to the thicker end' portions.

3. In sheet glass forming apparatus, the combination with a furnace containing a mass of molten glass and provided with an outlet through which a stream of molten glass issues, of means for directing the stream in a substantially-horizontalpath and reducing the same through successive stages to sheet form, including a plurality of pairs of sheet forming rolls, the rolls of the first .first at its center, and to then gradually re- Y pair adjacent lthe furnace tapering from their centers toward their opposite ends, and the last pair of rolls remotefrom the furnace being substantially cylindrical, and means for supporting the stream ofglass between adjacent pairs of forming rolls to prevent sagging of the thinner portions of the stream with respect to the thicker portions thereof.

4. In sheet glass forming apparatus, the'. combination with a furnace containlng a mass `of molten glass and provided with an outlet through which a stream ,ofmolten' glass issues, of means for directing the stream 1n a substantially horizontal ath and reducing the same through successlve stages to sheet .forming rolls to prevent the central thinner portion of the stream from sagging relative to the thicker end portions.

5.` 'In sheet glass forming. apparatus, the combinationwith a furnace containing a mass 11o form, including al plurality of pairs -of sheetV of molten glass and provided with an outlet through Whichy a stream of molten glass issues, of means for directing the stream in a substantially horizontal path and reducing the same through successive stages to sheet form, including a plurality of pairs of sheet forming rolls, the rolls of the firstpair adj acent lthe furnace tapering from-their centers toward their opposite ends, and the last pair of Vrolls remote from the furnace being substantially cylindrical, and glass supporting tables in advance of each pair of rolls 4for receiving the glass therefrom, the upper surface of each table being shaped to conform to the longitudinal contour of the lower roll of the preceding pair of rolls.

6. In sheet glass forming apparatus, the combination with a furnace containing a mass of molten glass and provided with an outlet through which a stream of molten glass issues, of means for directing the stream in a substantially horizontal pathl and reducing the same through successive'stages to sheet form, including a plurality of pairs of sheet forming rolls, the rolls of the first pair adjacent the furnape tapering from their centers toward their opposite ends with thesucceeding pairs of rolls gradually approaching cylindrical form, and a plurality of glass supporting tables between adjacent pairs of rolls for receiving the glass therefrom, the upper surfaces of said tables being shaped to conform to the longitudinal contour of the lower roll of the preceding pair oi' rolls.

7 The process of forming sheet glass, which consists in advancing a stream of molten glass in a generally horizontal .direction, reducing the thickness of the stream first at its center, in then reducing the end por tions of said stream to the saine thickness and in preventing sagging of the thinner portion of the stream relative to the thicker portions during. the reduction of said stream to sheet form.

. 8. Thew process of forming sheet glass,

which consists in advancing a stream of molten glass in a generally horizontal direction, reducing the thickness of the stream first at its'center, in then spreading the glass through successive stages from the center outwardly to gradually reduce the end portions of. said stream to the same thickness as the center and in preventing sagging of the central thinner portion of the stream relative to` the thicker end portions thereof during the reduction of said stream to sheet form.

Signed at`y Toledo, in the county of Lucas and State of Ohio, this 16th day of January,

WILLIAM E. NOBBE. 

